1. LIVING IN THE ENVIRONMENT 17 TH MILLER/SPOOLMAN Chapter 5 Biodiversity, Species Interactions, and Population Control

2. Core Case Study: Southern Sea Otters: Are They Back from the Brink of Extinction? Habitat Hunted: early 1900s Partial recovery Why care about sea otters? Ethics Tourism dollars Keystone species

3. Southern Sea Otter Fig. 5-1a, p. 104

4. 5-1 How Do Species Interact? Concept 5-1 Five types of species interactions— competition, predation, parasitism, mutualism, and commensalism—affect the resource use and population sizes of the species in an ecosystem.

5. Species Interact in Five Major Ways Interspecific Competition Predation Parasitism Mutualism Commensalism

6. Most Species Compete with One Another for Certain Resources For limited resources Ecological niche for exploiting resources Some niches overlap

7. Some Species Evolve Ways to Share Resources Resource partitioning Using only parts of resource Using at different times Using in different ways

8. Resource Partitioning Among Warblers Fig. 5-2, p. 106

9. Cape May Warbler Stepped Art Blackburnian Warbler Black-throated Green Warbler Yellow-rumped Warbler Bay-breasted Warbler Fig. 5-2, p. 106

10. Specialist Species of Honeycreepers Fig. 5-3, p. 107

11. Most Consumer Species Feed on Live Organisms of Other Species (1) Predators may capture prey by 1.Walking 2.Swimming 3.Flying 4.Pursuit and ambush 5.Camouflage 6.Chemical warfare

12. Predator-Prey Relationships Fig. 5-4, p. 107

13. Most Consumer Species Feed on Live Organisms of Other Species (2) Prey may avoid capture by 1.Run, swim, fly 2.Protection: shells, bark, thorns 3.Camouflage 4.Chemical warfare 5.Warning coloration 6.Mimicry 7.Deceptive looks 8.Deceptive behavior

14. Some Ways Prey Species Avoid Their Predators Fig. 5-5, p. 109

15. (d) Foul-tasting monarch butterfly (e) Poison dart frog Stepped Art (h) When touched, snake caterpillar changes shape to look like head of snake. (a) Span worm(b) Wandering leaf insect (c) Bombardier beetle (f) Viceroy butterfly mimics monarch butterfly (g) Hind wings of Io moth resemble eyes of a much larger animal. Fig. 5-5, p. 109

16. Science Focus: Threats to Kelp Forests Kelp forests: biologically diverse marine habitat Major threats to kelp forests 1.Sea urchins 2.Pollution from water run-off 3.Global warming

17. Purple Sea Urchin Fig. 5-A, p. 108

18. Predator and Prey Interactions Can Drive Each Other’s Evolution Intense natural selection pressures between predator and prey populations Coevolution Interact over a long period of time Bats and moths: echolocation of bats and sensitive hearing of moths

19. Coevolution: A Langohrfledermaus Bat Hunting a Moth Fig. 5-6, p. 110

20. Some Species Feed off Other Species by Living on or in Them Parasitism Parasite is usually much smaller than the host Parasite rarely kills the host Parasite-host interaction may lead to coevolution

21. Parasitism: Trout with Blood-Sucking Sea Lamprey Fig. 5-7, p. 110

22. In Some Interactions, Both Species Benefit Mutualism Nutrition and protection relationship Gut inhabitant mutualism Not cooperation: it’s mutual exploitation

23. Fig. 5-8, p. 110 Mutualism: Hummingbird and Flower

24. Mutualism: Oxpeckers Clean Rhinoceros; Anemones Protect and Feed Clownfish Fig. 5-9, p. 111

25. Fig. 5-9a, p. 111 (a) Oxpeckers and black rhinoceros

26. Fig. 5-9b, p. 111 (b) Clownfish and sea anemone

27. In Some Interactions, One Species Benefits and the Other Is Not Harmed Commensalism Epiphytes Birds nesting in trees

28. Commensalism: Bromiliad Roots on Tree Trunk Without Harming Tree Fig. 5-10, p. 111

29. 5-2 What Limits the Growth of Populations? Concept 5-2 No population can continue to grow indefinitely because of limitations on resources and because of competition among species for those resources.

30. Most Populations Live Together in Clumps or Patches (1) Population: group of interbreeding individuals of the same species Population distribution 1.Clumping 2.Uniform dispersion 3.Random dispersion

31. Most Populations Live Together in Clumps or Patches (2) Why clumping? 1.Species tend to cluster where resources are available 2.Groups have a better chance of finding clumped resources 3.Protects some animals from predators 4.Packs allow some to get prey

32. Population of Snow Geese Fig. 5-11, p. 112

33. Generalized Dispersion Patterns Fig. 5-12, p. 112

34. Populations Can Grow, Shrink, or Remain Stable (1) Population size governed by Births Deaths Immigration Emigration Population change = (births + immigration) – (deaths + emigration)

35. Populations Can Grow, Shrink, or Remain Stable (2) Age structure Pre-reproductive age Reproductive age Post-reproductive age

36. Some Factors Can Limit Population Size Range of tolerance Variations in physical and chemical environment Limiting factor principle Too much or too little of any physical or chemical factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance Precipitation Nutrients Sunlight, etc

37. Trout Tolerance of Temperature Fig. 5-13, p. 113

38. No Population Can Grow Indefinitely: J-Curves and S-Curves (1) Size of populations controlled by limiting factors: Light Water Space Nutrients Exposure to too many competitors, predators or infectious diseases

39. No Population Can Grow Indefinitely: J-Curves and S-Curves (2) Environmental resistance All factors that act to limit the growth of a population Carrying capacity (K) Maximum population a given habitat can sustain

40. No Population Can Grow Indefinitely: J-Curves and S-Curves (3) Exponential growth Starts slowly, then accelerates to carrying capacity when meets environmental resistance Logistic growth Decreased population growth rate as population size reaches carrying capacity

41. Logistic Growth of Sheep in Tasmania Fig. 5-15, p. 115

42. Science Focus: Why Do California’s Sea Otters Face an Uncertain Future? Low biotic potential Prey for orcas Cat parasites Thorny-headed worms Toxic algae blooms PCBs and other toxins Oil spills

43. Population Size of Southern Sea Otters Off the Coast of So. California (U.S.) Fig. 5-B, p. 114

44. Case Study: Exploding White-Tailed Deer Population in the U.S. 1900: deer habitat destruction and uncontrolled hunting 1920s–1930s: laws to protect the deer Current population explosion for deer Spread Lyme disease Deer-vehicle accidents Eating garden plants and shrubs Ways to control the deer population

45. Mature Male White-Tailed Deer Fig. 5-16, p. 115

46. When a Population Exceeds Its Habitat’s Carrying Capacity, Its Population Can Crash A population exceeds the area’s carrying capacity Reproductive time lag may lead to overshoot Population crash Damage may reduce area’s carrying capacity

47. Exponential Growth, Overshoot, and Population Crash of a Reindeer Fig. 5-17, p. 116

48. Species Have Different Reproductive Patterns (1) Some species Many, usually small, offspring Little or no parental care Massive deaths of offspring Insects, bacteria, algae

49. Species Have Different Reproductive Patterns (2) Other species Reproduce later in life Small number of offspring with long life spans Young offspring grow inside mother Long time to maturity Protected by parents, and potentially groups Humans Elephants

50. Under Some Circumstances Population Density Affects Population Size Density-dependent population controls Predation Parasitism Infectious disease Competition for resources

51. Several Different Types of Population Change Occur in Nature Stable Irruptive Population surge, followed by crash Cyclic fluctuations, boom-and-bust cycles Top-down population regulation Bottom-up population regulation Irregular

52. Population Cycles for the Snowshoe Hare and Canada Lynx Fig. 5-18, p. 118

53. Humans Are Not Exempt from Nature’s Population Controls Ireland Potato crop in 1845 Bubonic plague Fourteenth century AIDS Global epidemic

54. 5-3 How Do Communities and Ecosystems Respond to Changing Environmental Conditions? Concept 5-3 The structure and species composition of communities and ecosystems change in response to changing environmental conditions through a process called ecological succession.

55. Communities and Ecosystems Change over Time: Ecological Succession Natural ecological restoration Primary succession Secondary succession

56. Some Ecosystems Start from Scratch: Primary Succession No soil in a terrestrial system No bottom sediment in an aquatic system Takes hundreds to thousands of years Need to build up soils/sediments to provide necessary nutrients

57. Primary Ecological Succession Fig. 5-19, p. 119

58. Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (1) Some soil remains in a terrestrial system Some bottom sediment remains in an aquatic system Ecosystem has been Disturbed Removed Destroyed

59. Natural Ecological Restoration of Disturbed Land Fig. 5-20, p. 120

60. Secondary Ecological Succession in Yellowstone Following the 1998 Fire Fig. 5-21, p. 120

61. Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (2) Primary and secondary succession Tend to increase biodiversity Increase species richness and interactions among species Primary and secondary succession can be interrupted by Fires Hurricanes Clear-cutting of forests Plowing of grasslands Invasion by nonnative species

62. Science Focus: How Do Species Replace One Another in Ecological Succession? Facilitation Inhibition Tolerance

63. Succession Doesn’t Follow a Predictable Path Traditional view Balance of nature and a climax community Current view Ever-changing mosaic of patches of vegetation Mature late-successional ecosystems State of continual disturbance and change

64. Living Systems Are Sustained through Constant Change Inertia, persistence Ability of a living system to survive moderate disturbances Resilience Ability of a living system to be restored through secondary succession after a moderate disturbance Some systems have one property, but not the other: tropical rainforests

65. Three Big Ideas 1.Certain interactions among species affect their use of resources and their population sizes. 2.There are always limits to population growth in nature. 3.Changes in environmental conditions cause communities and ecosystems to gradually alter their species composition and population sizes (ecological succession).